1. Field of the Invention
The invention relates to a lighting device and a display device.
2. Description of the Related Art
Conventionally, incandescent bulbs or fluorescent lamps are used as light sources of, e.g., backlights of illuminated signs and liquid crystal displays or lighting equipments, etc. In recent years, since it has become possible to output high power from LEDs (Light Emitting Diode) as a point light source and intensity of illumination usable for lighting can be obtained, LEDs have been diversified as a light source alternative to incandescent bulbs or fluorescent lamps.
A lighting device, in which an illuminated area per LED is increased, has been proposed as a device using this type of LEDs for lighting (see, e.g., JP-A-2011-14831).
The lighting device described in JP-A-2011-14831 is provided with an LED extending in a direction orthogonal to an optical axis direction (in a longitudinal direction), a substrate mounting the LED, and a lens is provided so as to seal the LED on the surface of the substrate, the lens having a shape extending along the longitudinal direction to spread light of the LED in a width direction of the LED (a direction orthogonal to the longitudinal direction of the LED and to the optical axis direction). A light incident surface of the lens is optically coupled to a light-emitting surface of the LED by a coupling member.
However, in case of the lighting device described in JP-A-2011-14831 which is configured such that a back surface of the substrate is exposed from the lens, outdoor use thereof may lead to corrosion of wiring of the substrate or short-circuit because of rain water, etc. Thus, there is a problem in waterproof properties when using the lighting device outdoors. Meanwhile, use of a cover, etc., protecting from rain water, etc., allows the lighting device to be used outdoors but causes problems of an increase in the number of components of the lighting device and the resulting complicated structure, and optical loss caused by the cover is also a problem.